The wingspan of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777-200 has a wingspan of 60.93 metres, a wandering albatross caught in 1965 had a wingspan of 3.63 metres, the official record for a living bird. The term wingspan, more technically extent, is used for other winged animals such as pterosaurs, insects, etc. and other fixed-wing aircraft such as ornithopters. In humans, the term wingspan refers to the arm span, distance between the length from one end of an individual's arms to the other when raised parallel to the ground at shoulder height at a 90º angle. Former professional basketball player Manute Bol stands at 7 ft 7 in and owns one of the largest wingspans at 8 ft 6 in; the wingspan of an aircraft is always measured in a straight line, from wingtip to wingtip, independently of wing shape or sweep. The lift from wings is proportional to their area, so the heavier the animal or aircraft the bigger that area must be; the area is the product of the span times the width of the wing, so either a long, narrow wing or a shorter, broader wing will support the same mass.
For efficient steady flight, the ratio of span to chord, the aspect ratio, should be as high as possible because this lowers the lift-induced drag associated with the inevitable wingtip vortices. Long-ranging birds, like albatrosses, most commercial aircraft maximize aspect ratio. Alternatively and aircraft which depend on maneuverability need to be able to roll fast to turn, the high moment of inertia of long narrow wings produces lower roll rates. For them, short-span, broad wings are preferred; the highest aspect ratio man-made wings are aircraft propellers, in their most extreme form as helicopter rotors. To measure the wingspan of a bird, a live or freshly-dead specimen is placed flat on its back, the wings are grasped at the wrist joints and the distance is measured between the tips of the longest primary feathers on each wing; the wingspan of an insect refers to the wingspan of pinned specimens, may refer to the distance between the centre of the thorax to the apex of the wing doubled or to the width between the apices with the wings set with the trailing wing edge perpendicular to the body.
In basketball and gridiron football, a fingertip-to-fingertip measurement is used to determine the player's wingspan called armspan. This is called reach in boxing terminology; the wingspan of 16-year-old BeeJay Anya, a top basketball Junior Class of 2013 prospect who played for the NC State Wolfpack, was measured at 7 feet 9 inches across, one of the longest of all National Basketball Association draft prospects, the longest for a non-7-foot player, though Anya went undrafted in 2017. The wingspan of Manute Bol, at 8 feet 6 inches, is the longest in NBA history, his vertical reach was 10 feet 5 inches. Aircraft: Scaled Composites Stratolaunch — 117 m Aircraft: Hughes H-4 Hercules "Spruce Goose" – 97.51 m Aircraft Antonov An-225 Mriya - 88.4 m Bat: Large flying fox – 1.5 m Bird: Wandering albatross – 3.63 m Bird: Argentavis – Estimated 7 m Reptile: Quetzalcoatlus pterosaur – 10–11 m Insect: White witch moth – 28 cm Insect: Meganeuropsis – estimated up to 71 cm Aircraft: Starr Bumble Bee II – 1.68 m Aircraft: Bede BD-5 – 4.27 m Aircraft: Colomban Cri-cri – 4.9 m Bat: Bumblebee bat – 16 cm Bird: Bee hummingbird – 6.5 cm Insect: Tanzanian parasitic wasp – 0.2 mm
The Lockheed Constellation is a propeller-driven, four-engine airliner built by Lockheed Corporation between 1943 and 1958 at Burbank, California. Lockheed built 856 in numerous models—all with the same triple-tail design and dolphin-shaped fuselage. Most were powered by four 18-cylinder Wright R-3350 Duplex-Cyclones; the Constellation was used as a civil airliner and as a military and civilian air transport, seeing service in the Berlin and the Biafran airlifts. The Constellation series was the first pressurized-cabin civil airliner series to go into widespread use, its pressurized cabin enabled large numbers of commercial passengers to fly well above most bad weather for the first time, thus improving the general safety and ease of air-travel. Three of them served as the presidential aircraft for Dwight D. Eisenhower. Lockheed had been working on the L-044 Excalibur, a four-engine, pressurized airliner, since 1937. In 1939, Trans World Airlines, at the instigation of major stockholder Howard Hughes, requested a 40-passenger transcontinental airliner with a range of 3,500 mi —well beyond the capabilities of the Excalibur design.
TWA's requirements led to the L-049 Constellation, designed by Lockheed engineers including Kelly Johnson and Hall Hibbard. Willis Hawkins, another Lockheed engineer, maintains that the Excalibur program was purely a cover for the Constellation; the Constellation's wing design was close to that of the Lockheed P-38 Lightning, differing in size. The triple tail kept the aircraft's height low enough to fit in existing hangars, while features included hydraulically boosted controls and a de-icing system used on wing and tail leading edges; the aircraft had a maximum speed of over 375 mph, faster than that of a Japanese Zero fighter, a cruise speed of 340 mph, a service ceiling of 24,000 ft. According to Anthony Sampson in Empires of the Sky, Lockheed may have undertaken the intricate design, but Hughes' intercession in the design process drove the concept, capabilities and ethos; these rumors were discredited by Johnson. Howard Hughes and Jack Frye confirmed that the rumors were not true in a letter in November 1941.
With the onset of World War II, the TWA aircraft entering production were converted to an order for C-69 Constellation military transport aircraft, with 202 aircraft intended for the United States Army Air Forces. The first prototype flew on January 9, 1943, a short ferry hop from Burbank to Muroc Field for testing. Edmund T. "Eddie" Allen, on loan from Boeing, flew left seat, with Lockheed's own Milo Burcham as copilot. Rudy Thoren and Kelly Johnson were on board. Lockheed proposed the model L-249 as a long-range bomber, it received the military designation XB-30. A plan for a long-range troop transport, the C-69B, was canceled. A single C-69C, a 43-seat VIP transport, was built in 1945 at the Lockheed-Burbank plant; the C-69 was used as a high-speed, long-distance troop transport during the war. A total of 22 C-69s were completed before the end of hostilities, but not all of these entered military service; the USAAF cancelled the remainder of the order in 1945. However, some aircraft remained in USAF service into the 1960s, serving as passenger ferries for the airline that relocated military personnel, wearing the livery of the Military Air Transport Service.
At least one of these airplanes had rear-facing passenger seats. After World War II, the Constellation came into its own as a fast civilian airliner. Aircraft in production for the USAAF as C-69 transports were finished as civilian airliners, with TWA receiving the first on 1 October 1945. TWA's first transatlantic proving flight departed Washington, D. C. on December 3, 1945, arriving in Paris on December 4 via Shannon. TWA transatlantic service started on February 6, 1946 with a New York-Paris flight in a Constellation. On June 17, 1947, Pan American World Airways opened the first-ever scheduled round-the-world service with their L-749 Clipper America; the famous flight "Pan Am 1" operated until 1982. As the first pressurized airliner in widespread use, the Constellation helped to usher in affordable and comfortable air travel. Operators of Constellations included TWA, Eastern Air Lines, Pan Am, Air France, BOAC, KLM, Lufthansa, Iberia Airlines, Panair do Brasil, TAP Portugal, Trans-Canada Air Lines, Aer Lingus, VARIG, Cubana de Aviación, Línea Aeropostal Venezolana.
Sleek and powerful, Constellations set a number of records. On April 17, 1944, the second production C-69, piloted by Howard Hughes and TWA president Jack Frye, flew from Burbank, California, to Washington, D. C. in 6 hours and 57 minutes. On the return trip, the aircraft stopped at Wright Field in Ohio to give Orville Wright his last flight, more than 40 years after his historic first flight near Kitty Hawk, North Carolina, he commented. On September 29, 1957, a TWA L-1649A flew from Los Angeles to London in 32 minutes; the L-1649A holds the record for the longest-duration, non-stop passenger flight aboard a piston-powered airliner. On TWA's first London-to-San Francisco flight on October 1–2, 1957, the aircraft stayed aloft for 23 hours and 19 minutes. Jet airliners such as the de Havilland Comet, Boeing 707, Douglas DC-8, Convair 880, Sud Aviation Caravelle rendered the Constellation obsolete; the first routes lost to jet
Military Air Transport Service
For the current active command, see Air Mobility CommandThe Military Air Transport Service is an inactive Department of Defense Unified Command. Activated on 1 June 1948, MATS was a consolidation of the United States Navy's Naval Air Transport Service and the United States Air Force's Air Transport Command into a single joint command, it was inactivated and discontinued on 8 January 1966 when the Air Force and Military Airlift Command as a separate strategic airlift command and returned shore-based Navy cargo aircraft to Navy control as operational support airlift aircraft. In 1966, the World War II Air Transport Command and the Military Air Transport Service were consolidated with Military Airlift Command; the Military Air Transport Service was activated under United States Air Force Major General Laurence S. Kuter, in order to harness interservice efforts more efficiently, it was an amalgamation of Navy and Army air transport commands, jointly placed by the Department of Defense under the control of the newly created United States Air Force as a unified command.
During World War II, the Army Air Force's aerial transportation requirements were performed by the Air Transport Command which had a dual function of ferrying new aircraft from factories to combat theaters and transportation of troops and supplies organized by Tunner. The Naval Air Transport Service focused on supporting deployed Naval and Marine personnel transporting vital cargo, specialist personnel and mail to the Fleet and ground forces in advanced areas of operation. MATS was the first Joint-Service command and Naval aircrews participated in every major MATS airlift operation. MATS would organizationally be under the Department of the Air Force, as the vast majority of its equipment and personnel of ATC had been inherited by the Air Force with the inactivation of the USAAF. During the Berlin Airlift, Naval aviators flew transport aircraft from the United States to European supply depots. In its original organization, a Rear Admiral commanded the MATS Pacific Division and another rear admiral served as MATS vice-commander.
During the 1958 reorganization, senior Naval officers were on the staffs of the commanders of both EASTAF and WESTAF, at MATS Headquarters. In 1965 conflicting views of the Air Force and Navy triggered by the demands of the Vietnam War led to the services returning to separate airlift commands. In turn, MATS was disbanded and superseded in the Air Force by the Military Airlift Command, during a 1966 restructuring. With the end of World War II, the United States Army Air Forces Air Transport Command found itself in limbo. Senior USAAF authorities considered ATC to be a wartime necessity, no longer needed, expected its civilian personnel, including former airline pilots, to return to their peacetime occupations. Senior ATC officers, on the other hand, thought that ATC should be developed into a national government operated airline, an idea, soundly opposed by the airline industry. While the war had established the necessity of a troop carrier mission, most military officers believed the role performed by ATC should be provided by contract carriers.
When the United States Air Force was established as a separate service in 1947, the Air Transport Command was not established as one of its major commands. The ATC commander and his staff took it upon themselves to convince the new civilian leadership of the newly created Department of Defense that ATC had a mission, they seized upon testimony by former I Troop Carrier Command commander Major General Paul L. Williams that the Air Force should have a long-range troop deployment capability, began advocating that ATC transports could be used to deploy troops. Williams had been pressing for the development of a long-range troop carrier airplane when he made his statement; the DOD believed it should have its own air transport service and decided that ATC should become the Military Air Transport Service, supported by the Air Force though not listed as a formal military mission. As a cost-saving measure, MATS would combine the resources of Air Transport Command with those of the Naval Air Transport Service.
This way the command would be sanctioned by the Department of Defense, not by either the Air Force or the Navy. Although MATS was under the operational control of the United States Air Force, the United States Navy was a full partner in the command and operational components of the organization. Major naval components of MATS were naval air transport squadrons. VR-3 and VR-6 were assigned to McGuire AFB and VR-22 was assigned to the Naval Air Transport Station at Naval Station Norfolk/Chambers Field, Virginia. Together they constituted Atlantic. On the Pacific Coast, Naval Air Transport Wing, consisted of Air Transport Squadron VR-7 and Maintenance Squadron VR-8, both at Naval Air Station Moffett Field, California. A detachment of VR-7 was stationed at Tachikawa Air Base, Japan. Naval aviators flew scheduled MATS routes to Newfoundland, Scotland, West Germany, Puerto Rico and Africa. In the Pacific, MATS naval aviators flew to all MATS stations from Hawaii to Japan to South Vietnam, India and to Saudi Arabia.
Air Force pilots flew Navy MATS planes, just as naval aviators could be found piloting Air Force MATS transport aircraft. During World War II, the USAAF Air Transport Command provided worldwide transport service to every continent on the globe. Inheriting that legacy, MATS continued that service and organized it into three major transport divisions.
United States Air Force
The United States Air Force is the aerial and space warfare service branch of the United States Armed Forces. It is one of the five branches of the United States Armed Forces, one of the seven American uniformed services. Formed as a part of the United States Army on 1 August 1907, the USAF was established as a separate branch of the U. S. Armed Forces on 18 September 1947 with the passing of the National Security Act of 1947, it is the youngest branch of the U. S. Armed Forces, the fourth in order of precedence; the USAF is the largest and most technologically advanced air force in the world. The Air Force articulates its core missions as air and space superiority, global integrated intelligence and reconnaissance, rapid global mobility, global strike, command and control; the U. S. Air Force is a military service branch organized within the Department of the Air Force, one of the three military departments of the Department of Defense; the Air Force, through the Department of the Air Force, is headed by the civilian Secretary of the Air Force, who reports to the Secretary of Defense, is appointed by the President with Senate confirmation.
The highest-ranking military officer in the Air Force is the Chief of Staff of the Air Force, who exercises supervision over Air Force units and serves as one of the Joint Chiefs of Staff. Air Force components are assigned, as directed by the Secretary of Defense, to the combatant commands, neither the Secretary of the Air Force nor the Chief of Staff of the Air Force have operational command authority over them. Along with conducting independent air and space operations, the U. S. Air Force provides air support for land and naval forces and aids in the recovery of troops in the field; as of 2017, the service operates more than 5,369 military aircraft, 406 ICBMs and 170 military satellites. It has a $161 billion budget and is the second largest service branch, with 318,415 active duty airmen, 140,169 civilian personnel, 69,200 reserve airmen, 105,700 Air National Guard airmen. According to the National Security Act of 1947, which created the USAF: In general, the United States Air Force shall include aviation forces both combat and service not otherwise assigned.
It shall be organized and equipped for prompt and sustained offensive and defensive air operations. The Air Force shall be responsible for the preparation of the air forces necessary for the effective prosecution of war except as otherwise assigned and, in accordance with integrated joint mobilization plans, for the expansion of the peacetime components of the Air Force to meet the needs of war. §8062 of Title 10 US Code defines the purpose of the USAF as: to preserve the peace and security, provide for the defense, of the United States, the Territories and possessions, any areas occupied by the United States. The stated mission of the USAF today is to "fly and win...in air and cyberspace". "The United States Air Force will be a trusted and reliable joint partner with our sister services known for integrity in all of our activities, including supporting the joint mission first and foremost. We will provide compelling air and cyber capabilities for use by the combatant commanders. We will excel as stewards of all Air Force resources in service to the American people, while providing precise and reliable Global Vigilance and Power for the nation".
The five core missions of the Air Force have not changed since the Air Force became independent in 1947, but they have evolved, are now articulated as air and space superiority, global integrated intelligence and reconnaissance, rapid global mobility, global strike, command and control. The purpose of all of these core missions is to provide, what the Air Force states as, global vigilance, global reach, global power. Air superiority is "that degree of dominance in the air battle of one force over another which permits the conduct of operations by the former and its related land, sea and special operations forces at a given time and place without prohibitive interference by the opposing force". Offensive Counterair is defined as "offensive operations to destroy, disrupt, or neutralize enemy aircraft, launch platforms, their supporting structures and systems both before and after launch, but as close to their source as possible". OCA is the preferred method of countering air and missile threats since it attempts to defeat the enemy closer to its source and enjoys the initiative.
OCA comprises attack operations, sweep and suppression/destruction of enemy air defense. Defensive Counter air is defined as "all the defensive measures designed to detect, identify and destroy or negate enemy forces attempting to penetrate or attack through friendly airspace". A major goal of DCA operations, in concert with OCA operations, is to provide an area from which forces can operate, secure from air and missile threats; the DCA mission comprises both passive defense measures. Active defense is "the employment of limited offensive action and counterattacks to deny a contested area or position to the enemy", it includes both ballistic missile defense and air-breathing threat defense, encompasses point defense, area defense, high-value airborne asset defense. Passive defense is "measures taken to reduce the probability of and to minimize the effects of damage caused by hostile action without the intention of taking the initiative", it includes warning.
Wright R-3350 Duplex-Cyclone
The Wright R-3350 Duplex-Cyclone is a twin-row, air-cooled, radial aircraft engine with 18 cylinders displacing nearly 55 L. Power ranged from 2,200 to over 3,700 hp, depending on the model. Developed before World War II, the R-3350's design required a long time to mature before being used to power the Boeing B-29 Superfortress. After the war, the engine had matured sufficiently to become a major civilian airliner design, notably in its turbo-compound forms, was used in the Lockheed L-1049 Super Constellation airliners into the 1990s; the engine is now used on Hawker Sea Fury and Grumman F8F Bearcat Unlimited Class Racers at the Reno Air Races. Its main rival was Whitney R-4360 Wasp Major. In 1927, Wright Aeronautical introduced its famous "Cyclone" engine, which powered a number of designs in the 1930s. After merging with Curtiss to become Curtiss-Wright in 1929, an effort was started to redesign the engine to the 1,000 hp class; the new Wright R-1820 Cyclone 9 first ran in 1935, became one of the most-used aircraft engines in the 1930s and WWII, powering all frontline examples of the B-17 Flying Fortress Allied heavy bomber aircraft serving in the war, each powerplant assisted by a General Electric-designed turbocharger for maximum power output at high altitudes.
By 1931 Pratt & Whitney had started a development of their famous single-row, Wasp nine-cylinder design into a larger and much more powerful fourteen-cylinder, twin-row design — the Twin Wasp — of a nearly identical 30-liter displacement figure, that would compete with this larger, single-row Cyclone. In 1935 Wright followed P&W's lead, developed much larger engines based on the mechanics of the Cyclone; the result was two designs with a somewhat shorter stroke, a 14-cylinder design that would evolve into the Twin Cyclone, a much larger 18-cylinder design that became the R-3350. A larger twin-row 22-cylinder version, the R-4090, was experimented with as a competitor to the 71.5 litre-displacement four-row, 28-cylinder Pratt & Whitney Wasp Major, but was not produced. With Pratt & Whitney starting development of their own 46 liter-displacement 18-cylinder, twin-row high-output radial as the Double Wasp in 1937, Wright's first R-3350 prototype engines — itself having a nearly 55 liter displacement figure — were run in May of the same year.
Continued development was slow, both due to the complex nature of the engine, as well as the R-2600 receiving more attention. The R-3350 did not fly until 1941, after the prototype Douglas XB-19 had been redesigned from the Allison V-3420 to accept the R-3350. Things changed in 1940 with the introduction of a new contract by the USAAC to develop a long-range bomber capable of flying from the US to Germany with a 20,000 lb bomb load. Although smaller than the Bomber D designs that led to the Douglas XB-19, the new designs required the same amount of power; when preliminary designs were returned in the summer of 1940, three of the four designs were based on the R-3350. The engine was seen as the future of army aviation, serious efforts to get the design into production started. In 1942 Chrysler started the construction of the Dodge Chicago Plant and the new factory, designed by Albert Kahn, was in full operation by early 1944. By 1943 the ultimate development of the new bomber program, the Boeing B-29 Superfortress, was flying.
The engines remained temperamental, showed an alarming tendency for the rear cylinders to overheat due to minimal clearance between the cylinder baffles and the cowl. A number of changes were introduced into the Superfortress' production line to provide more cooling at low speeds, with the aircraft rushed into operational use in the Pacific in 1944; this proved unwise, as the early B-29 tactics of maximum weights, when combined with the high temperatures of the tropical airfields where B-29s were based, produced overheating problems that were not solved, the engines having an additional tendency to swallow their own valves. Because of a high magnesium content in the combustible crankcase alloy, the resulting engine fires — sometimes burning with a core temperature approaching 5,600 °F — were so intense the main spar could burn through in seconds, resulting in catastrophic wing failure. Early versions of the R-3350 had carburetors, though the poorly-designed elbow entrance to the supercharger led to serious problems with fuel/air distribution.
Near the end of WWII, the system was changed to use gasoline direct injection where fuel was injected directly into the combustion chamber. This improved engine reliability. After the war the engine was redesigned and became popular for large aircraft, notably the Lockheed Constellation and Douglas DC-7. Following the war the Turbo-Compound system was developed to deliver better fuel efficiency. In these versions, three power-recovery turbines were inserted into the exhaust piping of each group of six cylinders, geared to the engine crankshaft by fluid couplings to deliver more power; the PRTs recovered about 20% of the exhaust energy that would have otherwise been wasted, but reduced engine reliability. The fuel burn for the PRT-equipped aircraft was nearly the same as the older Pratt and Whitney R-2800, while producing more useful horsepower. Effective 15 October 1957 a DA-3/DA-4 engine cost $88,200. By this point reliability had improved with the mean time between overhauls at 3,500 hours and specific fuel consumption in the order of 0.4 lb/hp/hour (243 g/kWh, giving it a 3
Lockheed C-69 Constellation
The Lockheed C-69 Constellation was a four-engined, propeller-driven transport pressed into military service during World War Two. It was the first military version of the Lockheed Constellation aircraft line, it first flew in 1943, production of the 22 constructed was shared between the United States Army Air Forces and commercial carriers. Most of the C-69 aircraft built were converted into civilian airliners under the new designation L-049. Following the Attack on Pearl Harbor and the United States entering World War II, the assembly lines at the Lockheed Aircraft Corporation were taken over by the American government for the war effort. Along with the assembly lines, the Lockheed L-049 Constellation airliner was requisitioned and redesignated C-69 and was to be used as an equipment and personnel transport by the United States Army Air Forces. In February 1942, the 80 L-049/L-149 Constellations ordered by Transcontinental & Western Air and Pan American World Airways were requisitioned; the 50 L-049s both airlines had on order were to be redesignated C-69 and C-69A and used as troop transport aircraft.
The 30 L-149 aircraft Pan Am had on order were replaced by the similar model L-349 and designated C-69B. Another 180 C-69B aircraft were ordered increasing the figure to 210. Due to the direction the war was heading during summer 1942, the need for a large troop transport capable of crossing the Atlantic Ocean or Pacific Ocean became more important; this would help avoid the risks. The Douglas C-54 Skymaster planned for these roles wasn't capable. So on September 29, 1942, the American War Department signed contract W535 AC-26610. With this contract, the nine L-049 aircraft under construction for TWA were purchased and 150 more C-69A and C-69B aircraft were ordered along with C-69C and C-69D VIP transport versions. In reality, only one C-69C was produced out of all these planned variants. Around the same time the decision regarding contract W535 AC-26610 was made, the prototype XC-69 was completed and rolled out in December 1942; the aircraft was painted in olive green and grey camouflage colors and the civilian registration NX25600 along with Lockheed's logo being painted on the nose of the aircraft for promotional reasons.
However, problems developed with the Wright R-3350 Duplex-Cyclone. A consideration to replace the R-3350 engines with Pratt & Whitney R-2800 had been taken up; this led to a new version designated XC-69E, but the project was abandoned. On January 9, 1943, after the last inspections had been carried out by the USAAF and Lockheed, the XC-69 took to the skies. For the occasion, Lockheed had borrowed the Boeing Aircraft Company's chief test pilot, Edmund Allen. Allen was one of a small number of pilots to have experience with the R-3350 and was the test pilot for the Boeing B-29 Superfortress bomber, the role for which the R-3350 was developed. Lockheed test pilot Milo Burcham, known for flying the prototype Lockheed P-38 Lightning, acted as co-pilot during the flight. Both Allen and Burcham traded control of the aircraft during the entire experience. Both designers, Clarence "Kelly" Johnson and R. L. Thoren were present on the flight; the aircraft conducted four successful take-offs and landings. Burcham flew the XC-69 back to Burbank in 31 minutes.
In total, the XC-69 performed six separate flights all adding up to 129 minutes. Two aircraft, a Boeing B-17 Flying Fortress and a Lockheed L-18 Lodestar acted as photo chase aircraft. After the experience Allen commented, "This machine works so well that you don't need me anymore!" Allen returned to Boeing. A seventh flight took place on January 18; this time, the landing gear doors were placed on the aircraft. On July 28, 1943, the XC-69 was symbolically handed over to the USAAF at Las Vegas and given a military serial number 43-10309; that same day, the XC-69 returned to Lockheed for further testing. It is worth mentioning that the C-69 was able to attain a higher maximum speed than the Japanese Mitsubishi A6M Zero fighter. Major problems, surfaced with the R-3350 powerplant that powered the C-69, when an XB-29 test aircraft crashed into a Boeing factory; the accident killed 14 factory workers, Edmund Allen, the rest of Allen's test crew. The cause was due to one of the aircraft's R-3350 engines catching fire and burning through the wing of the aircraft causing it to fail and dooming the XB-29.
All aircraft fitted with the R-3350, including the C-69, were grounded until the investigation of the engine's failure was concluded. The conclusion led to a recommendation to replace the existing carburetors with more reliable ones. With that, testing resumed after June 18, 1943. A fuel leakage problem was discovered with the C-69 and wasn't solved until April 1944 when a new method of sealing the fuel tanks surfaced. More overheating and other troubles continued with the R-3350 engines; this happened to the point where Lockheed started to doubt the abilities of the engine's manufacturer, Curtiss-Wright. Lockheed suggested to the USAAF that the C-69's engines be replaced by more reliable R-2800 radial engines. Instead, the USAAF ceased production of the R-3350 until the troubles that plagued the engines were solved; this caused the development of the C-69 to slow down and
Lockheed EC-121 Warning Star
The Lockheed EC-121 Warning Star was an American Airborne early warning and control radar surveillance aircraft used from the 1950s by the United States Navy and United States Air Force. This military version of the Lockheed L-1049 Super Constellation was designed to serve as an airborne early warning system to supplement the Distant Early Warning Line, using two large radomes, a vertical dome above and a horizontal one below the fuselage; some EC-121s were used for intelligence gathering. It was introduced in 1954 and retired from service in 1978, although a single specially modified EW aircraft remained in service with the U. S. Navy until 1982; the U. S. Navy versions when procured were designated WV-1, WV-2, WV-3. Warning Stars of the U. S. Air Force served during the Vietnam War as both electronic sensor monitors and as a forerunner to the Boeing E-3 Sentry AWACS. U. S. Air Force aircrews adopted the civil nickname, "Connie" as reference, while naval aircrews used the term "Willie Victor" based on a slang version of the NATO phonetic alphabet and the Navy's pre-1962 "WV-" designations for the aircraft type.
Since 1943 the Lockheed Constellation had been in USAAF service as the C-69. The use of the Constellation by the U. S. Navy for patrol and airborne early warning duties was first investigated in 1949, when the Navy acquired two Lockheed L-749 Constellations. First flown on 9 June 1949, the PO-1W carried large, long-range radars in massive radomes above and below the fuselage; as the radomes possessed more side area, the vertical stabilizers of the PO-1W had to be enlarged. After the PO-1W, redesignated WV-1 in 1952, had proved that it was possible to operate large radars on aircraft, the U. S. Navy ordered the WV-2 based on the L-1049 Super Constellation; the WV-1s were transferred to the Federal Aviation Agency in 1958–1959. The WV-2/EC-121D was fitted with a dorsal AN/APS-45 height finder radar and a ventral AN/APS-20 air search radar; these radars were upgraded to AN/APS-103 and AN/APS-95 radars, although not simultaneously. The crew numbered 18, six officers and 12 enlisted personnel. However, when North Korea shot down a Navy EC-121 in 1969, a crew of 31 was on board.
Orders were placed totaling 142 PO-2W Constellations based on the Lockheed L-1049 Super Constellation with deliveries beginning in 1953. The type was redesignated WV-2 in 1954; the WV-2 was familiarly known to its crews as "Willy Victor". In 1962, with standardization of aircraft designations within the Department of Defense, the WV-2 became the EC-121K. A total of 13 of these were converted to WV-2Q electronic intelligence aircraft, nine were converted to WV-3 weather reconnaissance aircraft; the EC-121K was operated by Training Squadron 86 at NAS Glynco, Georgia for training of Student Naval Flight Officers destined to fly both the EC-121 and the Grumman E-2 Hawkeye. When NAS Glynco was closed and VT-86 transferred to NAS Pensacola, Florida in 1973, the squadron's last EC-121 was flown to NAS Pensacola for transfer to the collection of the National Museum of Naval Aviation where it remains today. A single aircraft became an NC-121K, an electronic warfare variant assigned to Tactical Electronic Warfare Squadron 33 at NAS Key West, Florida.
This aircraft was the last EC-121 in operational service, flying until 25 June 1982. The Air Force received 10 RC-121C and 74 EC-121D Warning Stars based on the L-1049 beginning with diversions from the Navy contracts in October 1953; the 10 RC-121Cs became trainers, designated TC-121C. Between 1966 and 1969, 30 retired Navy EC-121s were transferred to the USAF and converted in EC-121Rs as sensor-monitoring aircraft. Of the 74 EC-121s, 42 were converted to the EC-121H upgrade beginning in 1962, in 1969, 15 of the remaining EC-121Ds and seven of the EC-121Hs were further upgraded into the final operational variant, the EC-121T, which served as an AWACS prototype in Southeast Asia in 1972. Five EC-121Ds were modified to be broadcasting aircraft for psychological warfare operations, the predecessors of the EC-130 Commando Solo. WV-2s redesignated as EC-121s in 1962, served from 1954 to 1965 in two "barrier" forces, one off each coast of the North American continent; these barrier forces consisted of five surface picket stations each manned by radar destroyer escorts and an air wing of WV-2s/EC-121s that patrolled the picket lines at 1,000–4,000 m altitude in six- to 20-hour missions.
Their objective was to extend early warning coverage against surprise Soviet bomber and missile attack as an extension of the DEW Line. In April 1954 the first Lockheed Super Constellation, WV-2 BuNo. 128323, was received at NAS Barbers Point by Airborne Early Warning Squadron One. The Atlantic Barrier consisted of two rotating squadron detachments sourced from Airborne Early Warning Squadron THIRTEEN and Airborne Early Warning Squadron FIFTEEN home based at NAS Patuxent River and one squadron, Airborne Early Warning Squadron ELEVEN, permanently based at Naval Station Argentia, Newfoundland; the mission was to fly orbits to the Azores and back. There was an additional AEW Training Unit based at NAS Patuxent River for training flight crews and maintenance personnel. BarLant began operations on 1 July 1956, flew continuous coverage until early 1965; the Barrier was shifted to cover the approaches between Greenland and the United Kingdom barrier in June 1961. Aircraft from Argentia were staged through NAS Keflavik, Iceland, to extend co